Turk J Zool Research Article 33 (2009) 73-81 © TÜBİTAK doi:10.3906/zoo-0803-1 Some Turkish Rotifer Species Studied Using Light and Scanning Electron Microscopy Ahmet ALTINDAĞ1, Hendrik SEGERS2, Murat KAYA1,* 1Department of Biology, Faculty of Science, Ankara University, 06100 Beşevler, Ankara - TURKEY 2Royal Belgian Institute of Natural Sciences, Freshwater Biology, Vautierstraat 29, B-1000, Brussels, BELGIUM Received: 05.03.2008 Abstract: A number of records of rotifers from Turkey are discussed. An account is given on trophi morphology in 4 species of Asplanchna Gosse, 1850. Cephalodella segersi De Smet, 1998 is recorded for the second time after its description, and Lecane shieli Segers and Sanoamuang, 1994 is recorded from Turkey for the first time. Both these and a population of Hexarthra polyodonta polyodonta (Hauer, 1957) from the species’ type locality, Lake Van, are illustrated using light and scanning electron microscopic techniques. Key Words: Rotifera, trophi morphology, new records, Asplanchna, Cephalodella, Hexarthra, Turkey Işık ve Taramalı Elektron Mikroskobu Kullanarak Bazı Türkiye Rotifer Tür Çalışmaları Özet: Türkiye’den kaydedilen çok sayıda rotifer tartışıldı. Asplanchna Gosse, 1850’nin dört türünün trophi morfolojisi üzerine bir bilgi verildi. Cephalodella segersi De Smet, 1998 tanımlandığından sonra ikinci kez ve Lecane shieli Segers and Sanoamuang, 1994 ise Türkiye’den ilk kez kaydedildi. Hexarthra polyodonta polyodonta (Hauer, 1957)’nın bir populasyonu tip lokalitesinden ve diğer iki tür, ışık ve taramalı elektron mikroskobu (SEM) teknikleri kullanılarak şekillendirildi. Anahtar Sözcükler: Rotifera, trophi morfolojisi, yeni kayıtlar, Asplanchna, Cephalodella, Hexarthra, Türkiye Introduction According to José de Paggi (2002), the family The rotifer fauna of Turkey is relatively well known Asplanchnidae contains 15 species, 7 of which have been recorded from Turkey: Asplanchna brightwellii Gosse, (Ustaoğlu, 2004; Kaya et al., 2008), resulting in a total 1850; A. girodi de Guerne, 1888; A. priodonta Gosse, of 261 taxa recorded from the country. Nevertheless, it is 1850; A. sieboldii (Leydig, 1854); A. silvestrii Daday, clear that this figure is still far from complete: there are 1902; Asplanchnopus dahlgreni Myers, 1934; and A. only a few studies on the littoral and none on interstitial hyalinus Harring, 1913 (see Ustaoğlu, 2004; Erdoğan habitats of the region. As these are known to contain a and Güher, 2005). Numerous studies dealing with aspects highly diverse and specialised fauna, we expect that our of the taxonomy of the genus Asplanchna are available knowledge of the α-diversity of aquatic ecosystems in the (e.g., Salt et al., 1978; Gilbert et al., 1979; Koste and region is, at best, incomplete. The new records presented Shiel, 1980; Pourriot et al., 1984; Koste and Tobias, herein illustrate this. 1988; Shiel and Koste, 1993; José de Paggi, 2002); One genus of pelagic rotifers that has been recorded however, the diversity in the trophi morphology of these quite frequently worldwide is Asplanchna Gosse, 1850. animals is still insufficiently documented. * E-mail: [email protected] 73 Some Turkish Rotifer Species Studied Using Light and Scanning Electron Microscopy Materials and Methods Our specimens have a vitellarium containing 47-53 nuclei, Samples were collected using a 55-μm-mesh plankton and the trophi lack lamellae behind the rami apices. They net and preserved in 4% formalin. We used Leica DMLS are also relatively small (female body length 428-621 μm, and Olympus BX51 microscopes for identification and trophi 135-178 μm, fulcrum 21-23 μm versus body drawing of the species. Trophi were isolated by dissolving length 800-1150 μm in José de Paggi (2002). the soft body parts in dilute NaOCl, and were prepared Notwithstanding these differences, we tentatively identify for scanning electron microscopy (SEM) following the the specimens as Asplanchna silvestrii, considering that procedure of De Smet (1998a). SEM was performed Salt et al. (1978) identified similar specimens lacking using a JEOL JSM-60 60 LV on material processed with a lamellae behind the rami apices as such. Polaron SC 502 sputter-coater. Sampling locality: the Turkish specimens are from Lake Akşehir (ecology: inland freshwater, Konya, Turkey), and were collected from the pelagic zone in May Results and Discussion 1993. Lake Akşehir is a tectonic lake, and has a maximum Here, we report the results of a taxonomic study of surface of 35,000 ha. The deepest part of the lake is 7 m some rare Turkish rotifer species (Asplanchna deep. Coordinates: 38°26’52.89”N, 31°25’26.66”E; brightwellii, A. girodi, A. priodonta, Asplanchna silvestrii, altitude: 966 m (Altınsaçlı et al., 2000). This species, Cephalodella segersi, Hexarthra polyodonta polyodonta, which is not uncommon in the Americas, appears to be and Lecane shieli). Two of these, Cephalodella segersi and rare in the Old World. Lecane shieli, are of particular biogeographic relevance Asplanchna brightwellii Gosse, 1850 (Figures 9-15): and are new to the Turkish fauna. Vitellarium horseshoe-shaped containing 23-31 nuclei. Morphology of some Turkish Asplanchna species Our specimens are relatively small: Female body length Identification of Asplanchna species relies on 260-430 μm, trophi 133-197 μm, fulcrum 15-19 μm anatomical features as well as on trophi morphology (see versus body length 500-1500 μm, trophi 130-270 μm, in José de Paggi, 2002). Our material presents an extension José de Paggi (2002). of the known variability in several species: Asplanchna brightwellii resembles A. sieboldii, and Asplanchna silvestrii Daday, 1902 (Figures 1-8) has a these 2 species have often been confused. However, their horseshoe-shaped vitellarium containing 38-42 nuclei and trophi are diagnostic: those of A. brightwellii have has trophi bearing large lamellae behind the rami apices symmetrical lamellae behind the rami apices, whereas (Sarma and Elias-Guttierez, 1997; José de Paggi, 2002). those in A. sieboldii are asymmetrical. 25 µm 100 µm 15 µm 123 Figures 1-3. Asplanchna silvestrii. 1: habitus (contracted specimens), 2: vitellarium, 3: trophus. 1, 2: ventral view, 3: dorsal view. 74 A. ALTINDAĞ, H SEGERS, M KAYA 20 µm 5 4 20 µm 6 20 µm 7 8 5 µm 10 µm Figures 4-8. Trophi of Asplanchna silvestrii, SEM photographs. 4, 5, 7: dorsal view, 6, 8: ventral view. 50 µm 11 50 µm 50 µm 10 100 µm 9 12 Figures 9-12. Asplanchna brightwellii. 9: habitus (contracted specimens), 10. trophus, 11, 12: vitellarium. 9, 11, 12: ventral view, 10: dorsal view. 75 Some Turkish Rotifer Species Studied Using Light and Scanning Electron Microscopy Sampling locality: The material originates from Sampling locality: The samples were collected from the Sarımsaklı Dam Lake (Kayseri, Turkey), collected on 30 pelagic part of Ağcaşar Dam Lake (Kayseri, Turkey), on 25 August 2006. The samples were collected from the December 2005. Coordinates: 38°10’41.71”N, pelagic part of the lake. Coordinates: 38°53’16.50”N, 35°23’39.39”E; altitude: 292 m, ecology: alkali inland water. 35°44’26.30”E; altitude: 1330 m, ecology: inland Asplanchna girodi de Guerne, 1888 (Figures 19-21): freshwater. Our specimens are relatively small compared to the Asplanchna priodonta Gosse, 1850 (Figures 16-18): recorded range for the species [Female body length 453- The size of the specimens falls within the range given for 522 μm, trophi 78-89 μm, fulcrum 15-17 μm, versus the species by José de Paggi (2002): Female body length body length 500-700 μm, males 250-397 μm, trophi 93 479-553 μm, trophi 63-74 μm, fulcrum 14-16 μm. μm in José de Paggi (2002)]. r im t s m b a sa 10 μm 20 μm 13 10 μm 14 f 15 Figures 13-15. SEM trophi of Asplanchna brightwellii (a: apophysis, b: bulla, f: fulcrum, im: inner margin of the ramus, m: manubrium, r: ramus, s: scapus, sa: subapophysis, t: tooth of the ramus). 100 µm 50 µm 16 17 Figures 16, 17. Asplanchna priodonta. 16: habitus; 17: trophus. 16, 17: dorsal view. 76 A. ALTINDAĞ, H SEGERS, M KAYA Sampling locality: The samples are from Sarıkamış (Kars, Turkey), 16 July 1986 (coll. H. J. Dumont). Coordinates: 40°19’52.78”N, 42°34’43.14”E; altitude: 2750 m, ecology: inland freshwater. As far as can be judged from published records, Asplanchna sieboldii appears to be slightly more common in Turkey than A. brightwellii: A. sieboldii has been recorded from 11 different localities (Geldiay, 1949; Margaritora et al., 1977; Segers et al., 1992; Altındağ and Yiğit, 1999; Bekleyen, 2001; Bozkurt et al., 2002; Erdoğan and Güher, 2005; Bozkurt, 2006; Kaya and Altındağ, 2007), whereas A. brightwellii has been recorded from 7 localities, including the present study (Daday, 1903; Mann, 1940; Geldiay, 1949; Margaritora and Cottarelli, 1970; Dumont and De Ridder, 1987). This assessment is preliminary, however, as they have been 10 µm confused in the past. We hope that the present illustration of their trophi, and of those of the other species, will prevent further confusion. Other new or rare Turkish rotifers 18 Cephalodella segersi De Smet, 1998 (Figures 22-25): This species’ habitus, and toe and trophi shape indicate a close relationship with Cephalodella catellina (Müller, Figure 18. SEM trophus of A. priodonta. Ventral view. 1786) (De Smet, 1998b). They are easily distinguished, however, by their characteristic trophi: in C. segersi the right manubrium has an incompletely closed terminal loop 50 µm 100 µm 19 20 Figures 19, 20. Asplanchna girodi. 19: habitus, 20: trophus. 19: ventral view, 20: dorsal view. 77 Some Turkish Rotifer Species Studied Using Light and Scanning Electron Microscopy with a forked ventral arm; its left manubrium ends in an open loop with a simple ventral arm (Figures 24, 25). In C. catellina both manubria end in an incompletely closed loop with a simple ventral arm. C. segersi is furthermore la characterised by having a more prominent alula on its left ramus, and the less developed basal chamber of the right ramus (see De Smet, 1998b for more details).